I've read the specification for SWF file version 7 from Macromedia,
and thinking about if it possible to write a compiler, with an IDE
both running in Web client? Since JavaScript's poor performance, it is
almost impossible to write such a practical stuff in pure HTML with
JavaScript, but SWF has its internal "intrument set" just like a
simplified version of Java bytecode, you can do many simple
mathematical and logical operations with it, and you can also make a
great IDE with its powerful graphical user interface support with
ease.